Effect of Dietary Phytochemicals on Cancer Development
Fruits, vegetables, and common beverages as well as several herbs and plants, each having a variety of pharmacological properties, have been shown to be rich sources of microchemicals with the potential to prevent human cancers. Several epidemiological studies have suggested that microchemicals present in our diet could be the most desirable agents for the prevention and/or intervention of human cancer incidence and mortality due to stomach, colon, breast, esophagus, lung, bladder, and prostate cancer. Also, the consumption of vegetables and fruits often is lower in those who subsequently develop cancer. There are many biologically plausible reasons why consumption of plant foods might slow or prevent the appearance of cancer. The specific mechanisms of action of most phytochemicals in cancer prevention are not yet clear, but appear to be varied. Phytochemicals can inhibit carcinogenesis by induction of phase II enzymes and inhibiting phase I enzymes, scavenge DNA reactive agents, suppress the abnormal proliferation of early preneoplastic lesions, and inhibit certain properties of the cancer cell.